Foam introduction system including modified port geometry

ABSTRACT

A surgical apparatus for positioning within a tissue tract accessing an underlying body cavity includes a seal anchor member including leading portion, a trailing portion, and an intermediate portion disposed between the leading and trailing portions. The leading portion of the seal anchor member is configured and adapted to ease insertion of the seal anchor member into the tissue tract. Subsequent to insertion of the seal anchor member, the leading portion of the seal anchor member is also configured and adapted to facilitate securing and/or anchoring of the seal anchor member within the tissue tract.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/263,927 filed Nov. 24, 2009, the entire contents of which is hereby incorporated by reference herein.

BACKGROUND

1. Technical Field

The present disclosure relates generally to a seal for use in a surgical procedure. More particularly, the present disclosure relates to a seal anchor member adapted for insertion into an incision, or a naturally occurring bodily orifice, in tissue, and, for the sealed reception of one or more surgical objects such that a substantially fluid-tight seal is formed with both the tissue and the surgical object or objects.

2. Background of Related Art

A minimally invasive surgical procedure is one in which a surgeon enters a patient's body through a small opening in the skin or through a naturally occurring opening (e.g., mouth, anus, or vagina). Such procedures have several advantages over traditional open surgeries. In particular, as compared to traditional open surgeries, minimally invasive surgical procedures result in reduced trauma and recovery time for patients. Generally, such procedures are referred to as “endoscopic”, unless performed on the patient's abdomen, in which case the procedure is referred to as “laparoscopic”. Throughout the present disclosure, the term “minimally invasive” should be understood to encompass both endoscopic and laparoscopic procedures.

During a typical minimally invasive procedure, surgical objects, such as surgical access devices (e.g., trocar and cannula assemblies) or endoscopes, are inserted into the patient's body through the incision in tissue. In general, prior to the introduction of the surgical object into the patient's body, insufflation gases are used to enlarge the area surrounding the target surgical site to create a larger, more accessible work area. Accordingly, the maintenance of a substantially fluid-tight seal is desirable so as to prevent the escape of the insufflation gases and the deflation or collapse of the enlarged surgical site.

To this end, various valves and seals are used during the course of minimally invasive procedures and are widely known in the art. However, a continuing need exists for a seal anchor member that can be inserted directly into the incision in tissue and that can accommodate a variety of surgical objects while maintaining the integrity of an insufflated workspace.

SUMMARY

Disclosed herein is a surgical apparatus for positioning within a tissue tract accessing an underlying body cavity. The surgical apparatus includes a seal anchor member including a leading portion, a trailing portion, and an intermediate portion disposed between the leading and trailing portions. One or more lumens longitudinally extend between the leading and trailing portions. The one or more lumens are configured and adapted to receive instrumentation therein in a substantially sealed relation.

The leading portion of the seal anchor member is transitionable between a first configuration and a second configuration. The arrangement and/or interrelationship between the elements, e.g., the elements of the leading portion of the seal anchor member may be different in the first and second configurations. For example, the positioning of elements with respect to each other may differ in the first and second configurations. The leading portion may define a radial dimension, diameter or a width that corresponds to each of the first and second configurations. In an embodiment, the leading portion includes a plurality of positioning members defining at least one gap between adjacent positioning members to facilitate compression of the leading portion in a transverse direction. The at least one gap facilitates transitioning the leading portion to the second configuration in which the leading portion has a substantially flat profile, thereby facilitating insertion of the seal anchor member within the tissue tract.

In another embodiment, the leading portion of the seal anchor member may include one or more positioning segments that are radially coupled to the intermediate portion of the seal anchor member, e.g., the one or more positioning members are operably connected to the intermediate portion. To facilitate insertion of the seal anchor member within the tissue member the one or more positioning members are inwardly directed to minimize the size of the leading portion of the seal anchor member. Once inserted into the tissue tract, the one or more positioning members may deploy outwardly, thereby increasing the size of the leading portion of the seal anchor member and facilitating stabilization and/or anchoring of the seal anchor member within the tissue tract. The one or more positioning members may be biased inwardly, and may deflect outwardly in response to insertion of instrumentation through the lumens of the seal anchor member.

In yet another embodiment, a seal anchor member may include a leading portion, a trailing portion, and an intermediate portion disposed therebetween. A first positioning member may be associated with the trailing portion, and a second positioning member may be associated with the leading portion. The second positioning member may have a non-circular, e.g., an oblong shape or configuration. The non-circular shape of the second positioning member facilitates insertion by guiding the seal anchor member to a proper position within the tissue tract. Once positioned within the tissue tract, the non-circular shape of the second positioning member also facilitates anchoring and/or securing of the seal anchor member within the tissue tract. The seal anchor member may also include one or more longitudinally extending lumens between the leading and trailing portions of the seal anchor member.

These and other features of the apparatus disclosed herein will become more readily apparent to those skilled in the art from the following detailed description of various embodiments of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present disclosure are described hereinbelow with reference to the drawings, wherein:

FIG. 1 is a perspective view of a seal anchor member in accordance with the principles of the present disclosure shown in a first condition positioned relative to tissue;

FIG. 2 is a bottom view of the seal anchor member of FIG. 1;

FIG. 3 is a bottom view of the seal anchor member of FIG. 1 shown in a second condition;

FIG. 3A is a bottom view of a seal anchor member having a single annular positioning member;

FIG. 4 is a perspective view of another embodiment of a seal anchor member in accordance with the principles of the present disclosure shown in a first condition;

FIG. 5 is a perspective view of the seal anchor member of FIG. 4 shown partially inserted within tissue;

FIG. 6A is a perspective view of yet another embodiment of a seal anchor member in accordance with the principles of the present disclosure shown in a first condition;

FIG. 6B is a perspective view of the seal anchor member of FIG. 6A shown in a second condition;

FIG. 7A is perspective view of the seal anchor member of FIG. 6A, shown placed within a wound within a tissue, while in the first condition;

FIG. 7B is a perspective view of the seal anchor member of FIG. 6A, shown placed within a wound within a tissue, while in the second condition;

FIG. 8 is a top perspective view of yet another embodiment of a seal anchor member in accordance with the present disclosure;

FIG. 9 is a bottom perspective view of the seal anchor member of FIG. 8;

FIG. 10 is a top view of the seal anchor member of FIG. 8;

FIG. 11 is a side view of the seal anchor member of FIG. 8;

FIG. 12 is a top, partially cut-away view of the seal anchor member of FIG. 8;

FIG. 13 is a side cross-sectional view of the seal anchor member of FIG. 8 taken along section-line 13 as shown in FIG. 12;

FIG. 14 is a perspective view of the seal anchor member of FIG. 8 shown placed within an incision in a first condition;

FIG. 15 is a side cross-sectional view, taken along section-line 15-15, of the seal anchor member of FIG. 8 as shown in FIG. 14; and

FIG. 16 is a side cross-sectional view of the seal anchor member of FIG. 8 as shown in FIG. 15 in a second condition.

DETAILED DESCRIPTION OF EMBODIMENTS

In the figures and in the description that follows, in which like reference numerals identify similar or identical elements, the term “proximal” will refer to the end of the apparatus that is closest to the clinician during use, while the term “distal” will refer to the end that is farthest from the clinician, as is traditional and known in the art.

With reference to FIGS. 1-3, a seal anchor member 100 will now be described. Seal anchor member 100 includes a body 112 defining a longitudinal axis “A” and having respective trailing (proximal) and leading (distal) portions 102, 104, and an intermediate section 106 disposed between the trailing and leading portions 102, 104. Seal anchor member 100 includes one or more ports 108 a, 108 b, 108 c that extend generally longitudinally between trailing and leading portions 102, 104, respectively, and through seal anchor member 100.

Associated with trailing and leading portions 102, 104 are positioning members 116 and 114 a-d, respectively. Positioning members 116, 114 a-d may be composed of any suitable material that is at least semi-resilient to facilitate resilient deformation of the positioning members 116, 114 a-d. The positioning members 116, 114 a-d may exhibit any suitable configuration and may be, for example, substantially annular-shaped or oval-shaped arrangement. As shown in FIG. 2, a diameter of the leading portion 104, when in its initial, expanded, condition, has dimension “De”.

As shown best in FIG. 2, associated with the leading portion 104 are positioning members 114 a-d that are separated by surfaces 115 a-d that define gaps among positioning members 114 a-d. While four positioning members 114 a-d are depicted in FIGS. 1-3, a greater or lesser number of positioning members, configured to define gaps therebetween, may be utilized to achieve a desired configuration of the seal anchor member 100 when compressed.

For insertion of seal anchor member 100 within a tissue tract 12, positioning members 114 a-d are brought in closer proximity to one another to facilitate placement of the seal anchor member 100 within the tissue tract. The separation between the positioning members 114 a-d facilitates transition of the distal portion 104 between a substantially annular profile (FIG. 2) to a substantially rectangular profile (FIG. 3). The gaps between the positioning members 114 a-d help facilitate the transition of leading portion 104 to a substantially flatter profile, such that distal portion 104 has a dimension “Dc”, as shown in FIG. 3, upon application of a force “F” than may have been achievable in the absence of such gaps. In particular, if the distal portion 104 included only a single annular positioning member, compression of the distal end 104 would result in a non-uniform contour (FIG. 3A) of the seal anchor member 100, e.g., the seal anchor member 100 would be compressed more greatly, e.g., would be flatter, at the point of the application of the force and less greatly farther away from that point.

Subsequent to insertion of the seal anchor member 100 within the tissue tract, the resilient nature of the positioning members 114 a-d, 116 allows the positioning members to expand to approximate the tissue tract 12 when seal anchor member 100 is inserted. Positioning members 114 a-d, 116 may engage walls defining the body cavity to further facilitate securement of seal anchor member 100 within the body tissue “T”. For example, positioning members 114 a-d at leading portion 104 may engage the internal peritoneal wall and positioning member 116 adjacent trailing portion 102 may engage the outer epidermal tissue adjacent the incision 12 within tissue “T”.

The use and function of seal anchor member 100 during the course of a typical minimally invasive procedure will now be discussed. Initially, an incision is made through the tissue. Such an incision is typically made with a scalpel or the like, resulting in a generally slit-shaped opening. Next, a body cavity, e.g., the peritoneal cavity, is insufflated with a suitable biocompatible gas such as, e.g., carbon dioxide, such that the cavity wall is raised and lifted away from the internal organs and tissue housed therein, providing greater access thereto. Insufflation of the body cavity may be performed with an insufflation needle or similar device, as is conventional in the art.

The seal anchor member 100 is in an expanded state at rest, as shown in FIG. 2. Insertion of the seal anchor member 100 within the tissue tract 12 is achievable by compressing the leading portion 104 of the seal anchor member 100. Positioning member 114 is adapted and configured to become substantially flat (when viewed from below) upon the application of a force “F” as seen in FIG. 3. Compression of the seal anchor member 100 facilitates insertion of the seal anchor member 100 into the tissue tract 12. Subsequent to the insertion of the seal anchor member 100, leading portion 104, positioning members 114 a-d and at least a section 112 of intermediate portion 106 are disposed beneath tissue “T”. Seal anchor member 100 is caused to transition from the compressed state as shown in FIG. 3 towards the expanded state (FIG. 1) by removing force “F” therefrom. Expansion of the section 112 of the intermediate portion 106 is limited by the tissue surfaces 14 (FIG. 1) defining tissue tract 12, thereby subjecting intermediate portion 106 to an external force “F” that is directed inwardly. The internal biasing force of seal anchor member 100 is outwardly directed and is exerted upon tissue surfaces 14 upon insertion of the seal anchor member 100 within tissue tract 12, thereby facilitating a substantially fluid-tight seal between the seal anchor member 100 and tissue surfaces 14 and substantially preventing the escape of insufflation gas around seal anchor member 100 and through tissue tract 12.

In the expanded condition, the respective radial dimensions D₁, D₂ of the trailing and leading portions 102, 104 are substantially larger than the radial dimension R of the intermediate portion 106 thereby giving seal anchor member 100 an “hour-glass” configuration. Subsequent to insertion, the radial dimension D₂ of distal portion 104 increases to provide an interference fit with the tissue tract 12. Consequently, seal anchor member 100 resists removal from tissue tract 12 when in the expanded condition and thus, seal anchor member 100 will remain anchored within the tissue “T” until it is returned to its compressed condition and is pulled out of the tissue tract 12.

Optionally, as shown in FIGS. 1-2, each of the positioning members 114 a-d at the distal portion 104 of the seal anchor member 100 may include a lumen 118 a, 118 b, 118 c, 118 d, respectively. Lumens 118 a-d are configured and adapted to receive a drawstring 117 therein. Seal anchor member 100 may further include a longitudinally extending lumen 119 adapted for reception of the drawstring 117. During a procedure, the surgeon may move the drawstring 117 through lumen 119 by pulling the drawstring 117 in a proximal direction thereby reducing the length of the drawstring 117 positioned within lumens 118 a-d. Moving the drawstring 117 through lumen 119 forces the positioning members 114 a-d to move toward one another thereby reducing the gaps defined among the positioning members 114 a-d.

During a surgical procedure, the surgeon places the seal anchor member 100 relative to the tissue tract 12 of the tissue “T”, as shown in FIG. 1. As discussed above, the size of the distal portion (leading portion) 104 is reduced by proximally pulling the drawstring 117. Once the distal portion 104 is sufficiently compressed (FIG. 3), the surgeon inserts the distal portion 104 into the tissue tract 12. With the distal portion 104 compressed, the seal anchor member 100 may taper from the proximal (trailing) to the distal (lead) portions of the seal anchor member 100. Both the reduced cross-section of the distal portion 104 and the resulting taper of the seal anchor member 100 facilitate the surgeon's insertion of the seal anchor member 100 into the tissue tract 12.

The internal bias of the seal anchor member 100 will apply a force to transition the distal portion 104 back to its initial dimension “De”. Therefore, during insertion of the seal anchor member, the surgeon may continue to pull drawstring 117 proximally to maintain the compressed dimension “Dc” of the distal portion 104. The material of the seal anchor member 100, e.g., a foam, may also facilitate a timed transition back to the initial shape and dimension of the seal anchor member 100, thereby reducing the need to apply tension to the drawstring 117 during insertion. In an embodiment, a clip or another locking means may be employed to secure the drawstring 117 in a given position, thereby maintaining a given dimension of the distal portion 104 by inhibiting the translation of the drawstring 117 through the lumen 119.

Once the surgeon has placed the seal anchor member 100 within the tissue tract 12 as desired, the surgeon will permit the drawstring 117 to translate. The internal biasing force of the seal anchor member 100 will begin to transition the distal portion 104 to the expanded dimension “De”. In the expanded state, the shape and configuration of the seal anchor member 100 facilitates anchoring of the seal anchor member 100 within the tissue tract 12. Once the seal anchor member 100 is anchored within the tissue tract 12, surgical instruments are inserted through lumens 108 a-c.

Upon completion of the procedure, the instruments are removed, and the drawstring 117 is once again translated proximally through lumen 119 to reduce the dimension of the distal portion 104 toward the compressed dimension “Dc”. Thereafter, the surgeon removes the seal anchor member 100 from the tissue tract 12. The reduced dimension of the distal portion 104 facilitates withdrawal of the seal anchor member 100 from within the tissue tract 12 of tissue “T”. The tissue tract 12 may then be closed through means known in the art, e.g., stapling or suturing.

In another embodiment of the present disclosure, a seal anchor member 200 will now be described with reference to FIGS. 4 and 5. As shown best in FIG. 4, the seal anchor member 200 defines a longitudinal axis “B” and having respective trailing (or proximal) and leading (or distal) portions 202, 204 and an intermediate portion 206 disposed between the trailing and leading portions 202, 204. Seal anchor member 200 includes one or more ports 208 a, 208 b, 208 c that extend longitudinally between trailing and leading portions 202, 204, respectively, and through seal anchor member 200. Positioning members 213, 214 are respectively associated with trailing portion 202 and leading portion 204.

Positioning member 214 has a non-circular, in this case, oblong shape. In an embodiment as shown in FIG. 4, the positioning member 214 has an oblong shape. The oblong shape of the positioning member 214 facilitates insertion of the seal anchor member 200 into the tissue tract 12. Distal portion 214 a of positioning member 214 is configured to guide the seal anchor member 200 into the tissue tract 12.

Placement of the seal anchor member 200 within the tissue tract 12 will now be described with reference to FIG. 5. As seen in FIG. 5, introduction of the seal anchor member 200 is achieved by placing distal portion 214 a within the tissue tract and translating the seal anchor port 200 along directional arrow “D” to place leading portion 204 within tissue tract 12. Surgical instruments may be used to grasp and position the leading portion 204 of the seal anchor member 200. Alternatively, a surgeon may select to grasp and position the leading portion 204 of the seal anchor member 200 with his or her hand. Upon placement of the seal anchor member 200 within the tissue tract 12, the surgeon may place instruments within the lumens 208 a-c.

Upon completion of the procedure, the seal anchor member 200 is removed from within the tissue tract 12. The seal anchor member 200 may be removed by translating the seal anchor member along a path opposite that defined by directional arrow “D”. In addition, the seal anchor member 200 may be formed from a compressible material. Where the seal anchor member 200 is formed from a compressible material, the surgeon may reduce the dimensions of the seal anchor member 200 by squeezing the seal anchor member 200. The reduction in the dimensions of the seal anchor member 200 may also facilitate the removal of the seal anchor member 200 from within the tissue tract 12. The tissue tract 12 may then be closed through means known in the art, e.g., stapling or suturing.

With reference to FIGS. 6A-6B, a seal anchor member 300 will now be described. The seal anchor member 300 includes a trailing (proximal) portion 302, a leading (distal) portion 304, and an intermediate section 306 disposed between the trailing and leading portions 302, 304. The seal anchor member 300 includes one or more longitudinally extending lumens 308 a, 308 b. Each of the lumens 308 a-b is configured and adapted to receive a surgical instrument “I” (FIG. 7B) therethrough in a substantially sealed relationship.

The leading portion 304 includes one or more positioning segments 304 a, 304 b. The positioning segments 304 a, 304 b are operably connected to the intermediate section 306 by a living hinge 310 a, 310 b, respectively. While the positioning segments 304 a-b are shown as being operably connected to the intermediate section 306 by a living hinge, other types of hinges may be used to facilitate the pivotal relationship between the intermediate section 306 and the positioning segments 304 a-b. As shown in FIG. 6A, the seal anchor member 300 is in a first, collapsed position in which positioning segments 304 a, 304 b are inwardly retracted such that the leading portion 304 defines a first diameter D₃. In the second, expanded position (FIG. 6B), the positioning segments 304 a, 304 b have been deployed radially outward as indicated by directional arrows G, H, respectively. While in the second position, the leading portion 304 defines a second diameter D₄ that is greater than the first diameter D₃. Transitioning of the seal anchor member 300 between the first and second positions necessitates application of a force sufficient to radially translate the positioning segments 304 a, 304 b.

As shown in FIG. 7A, when the seal anchor member 300 is in the first, collapsed position, placement of the seal anchor member 300 within opening “O” of the tissue “T” is facilitated by having a comparatively smaller diameter. In addition, the comparatively smaller diameter may reduce the overall size of the opening “O” necessary to place the seal anchor member 300 within the opening “O”. As shown in FIG. 7B, insertion of surgical instruments “I” through the lumen 308 a, 308 b effects deployment of a corresponding positioning segment 304 a, 304 b. In particular, insertion of surgical instrument “I” through lumen 308 a effects a radial translation of positioning segment 304 a in the direction indicated by arrow G. Similarly, insertion of surgical instrument “I” through lumen 308 b effects a radial translation of positioning segment 304 b in the direction indicated by directional arrow H.

With the positioning segments 304 a, 304 b deployed, the seal anchor member 300 is anchored within the opening “O” of the tissue “T”. In particular, while the positioning segments 304 a, 304 b are in the deployed condition, the interaction of the positioning segments 304 a, 304 b with the tissue “T” inhibits the removal of the seal anchor member 300 from the opening “O”. In particular, when the leading portion 304 is in the second position, the diameter D₄ is greater than the opening of opening “O”, thereby inhibiting removal of the seal anchor member 300.

With the positioning segments 304 a, 304 b retracted, the seal anchor member 300 is inserted into the opening “O”. Thereafter, the instruments “I” are inserted into lumens 308 a, 308 b. The insertion of the instruments “I” into lumens 308 a, 308 b effects a corresponding deployment of the positioning segments 304 a, 304 b in the direction indicated by arrows G, H, respectively. Upon completion of the surgical procedure, the seal anchor member 300 is removed from the opening “O” as will now be described. Each of the instruments “I” is removed from the lumen 308 a, 308 b into which it was placed. The removal of the instruments “I” effects retraction of the positioning segments 304 a, 304 b since the positioning segments 304 a, 304 b are biased inwardly. The retraction of the positioning segments 304 a, 304 b facilitates removal of the seal anchor member 300 by reducing the dimension of the leading portion 304 of the seal anchor member 300, i.e., distal portion 304 has a diameter D₃ that is less than the opening of the opening “O”. Thereafter, the surgeon proximally translates the seal anchor member out of the opening “O”. The opening “O” may then be closed through means known in the art, e.g., stapling or suturing.

With reference to FIGS. 8-16, a seal anchor member 400 will now be described. The seal anchor member 400 includes a trailing or a proximal portion 416, a leading or distal portion 414, and an intermediate section 406 disposed therebetween. The seal anchor member 400 includes one or more longitudinally extending lumens 408-d. Each lumen 408 a-d is configured and adapted to receive a surgical instrument “I” (FIGS. 14-16) therethrough in a substantially sealed relationship. As shown best in FIG. 9, the leading portion 414 includes four positioning segments 404 a-d. Although the leading portion 414 is illustrated and described herein as including four positioning segments 404 a-d, the leading portion 414 may include a fewer or greater number of positioning segments, e.g., three positioning segments. Each positioning segment 404 a-d is operably connected to the intermediate section 406 by a living hinge 410 a-d, respectively. Although the positioning segments 404 a-d are shown as being operably connected to the intermediate section 406 by a living hinge 410 a-d, other types of hinges may be used to facilitate the pivotal relationship between the intermediate section 406 and the positioning segments 404 a-d.

The positioning segments 404 a-d are biased inwardly such that in the absence of a force acting upon them, the positioning segments 404 a-d are retracted. While the positioning segments 404 a-d are in the retracted position, the leading portion 414 is in a first position and defines a first dimension “Q” to facilitate insertion of the seal anchor member 400 into an opening “O” within a tissue “T” (FIG. 15). Insertion of instrumentation “I” into the lumens 408 a-d, effects deployment of respective positioning members adjacent the lumens 408 a-d through which the instrumentation “I” is inserted (FIG. 16). While the positioning segments 404 a-d are in the deployed position, the leading portion 414 is in a second position and defines a dimension “R”, which facilitates anchoring of the seal anchor member 400 within the opening “O”. In particular, when the leading portion 414 is in the first position (FIG. 15), the dimension “Q” is less than the opening of opening “O”, thereby facilitating insertion of the seal anchor member 400 into the opening “O”. When the leading portion 414 is in the second position (FIG. 16), the dimension “R” is greater than the opening of opening “O”, thereby inhibiting removal of surgical seal anchor 400.

The use and operation of seal anchor member 400 will now be described with reference to FIGS. 14-16. As shown in FIG. 14, when the seal anchor member 400 is in a first, collapsed position, i.e., with positioning segments 404 a-d retracted, the seal anchor member is placed within opening “O” within tissue “T”. As discussed above, the positioning segments 404 a-d are biased inwardly towards the retracted state such that the leading portion defines a dimension “Q” to facilitate insertion of the seal anchor member 400 into the opening “O” within tissue “T”. Surgical instrumentation “I” may be partially inserted within the lumens 408 a-d during the placement of the seal anchor member 400 within the opening “O” or may be inserted into the lumens 408 a-d subsequent to placement of the seal anchor member 400 within the opening “O”.

The distal translation of the instrumentation “I” within the lumens 408 a-d will effect deployment of the positioning segments 404 a-d as the instrumentation “I” comes into contact with the positioning segments 404 a-d. Insertion of instrumentation “I” through a lumen 408 a-d effects the deployment of a corresponding positioning member 404 a-d, i.e., a positioning member 404 a-d that is along the path through which the instrument “I” is translated. As shown in FIG. 16, the distal translation of the instrumentation “I” through lumens 408 b, 408 d, effects the radial, outward deflection of corresponding positioning segments 404 b, 404 d. Anchoring of the seal anchor member 400 within the opening “O” is achieved through the insertion of instruments “I” into each lumen 408 a-d. However, in some situations, some of the lumens 408 a-d may not have an instrument inserted therethrough. In those situations, stabilization of the seal anchor member 400 may be enhanced by inserting the instruments “I” a symmetrical pattern, i.e., pairs of instruments “I” may be inserted within lumens 408 a-d that are across from one another.

Subsequent to completion of the procedure, removal of the seal anchor member 400 is facilitated by removing the instruments “I” from each lumen 408 a-d. Since the positioning members 404 a-d are biased toward the initial, retracted state, the leading portion 414 will transition toward smaller dimension “Q” from the greater dimension “R”. This reduction in the dimension of the leading portion 414 facilitates removal of the seal anchor member 400 from within incision “I” formed within tissue “T”.

Although the illustrative embodiments of the present disclosure have been described herein with reference to the accompanying drawings, the above description, disclosure, and figures should not be construed as limiting, but merely as exemplifications of particular embodiments. It is to be understood, therefore, that the disclosure is not limited to those precise embodiments, and that various other changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the disclosure. 

1. A surgical apparatus for positioning within a tissue tract accessing an underlying body cavity, comprising: a seal anchor member comprising: a leading portion; a trailing portion; an intermediate portion disposed between the leading and trailing portions; and one or more lumens longitudinally extending between the leading and trailing portions, wherein the leading portion is transitionable between a first configuration and a second configuration.
 2. The surgical apparatus of claim 1, wherein the first configuration has a first arrangement of elements, and the second configuration has a second arrangement of elements.
 3. The surgical apparatus of claim 1, wherein the leading portion has a first diameter in the first configuration and a second diameter in the second configuration, the first diameter different from the second diameter.
 4. The surgical apparatus of claim 1, wherein the transition between the first and second configurations is in response to insertion of a surgical instrument through at least one of the lumens.
 5. The surgical apparatus of claim 1, wherein the leading portion comprises a plurality of positioning members defining at least one gap between adjacent positioning members to facilitate compression of the leading portion in a transverse direction.
 6. The surgical apparatus of claim 1, wherein the leading portion has a substantially flat profile in the second configuration.
 7. The surgical apparatus of claim 1, wherein the leading portion includes one or more positioning segments, the positioning segments radially translatable with respect to the intermediate portion.
 8. The surgical apparatus of claim 7, wherein the one or more positioning segments are inwardly directed while in the first configuration to facilitate insertion of the leading portion into the tissue tract.
 9. The surgical apparatus of claim 7, wherein the one or more positioning segments are outwardly directed while in the second configuration to facilitate anchoring of the seal anchor member within the tissue tract.
 10. The surgical apparatus of claim 7, wherein the one or more positioning segments are inwardly biased.
 10. The surgical apparatus of claim 7, wherein the one or more positioning segments radially translate to be outwardly directed in response to insertion of an instrument through the one or more lumens.
 11. A surgical apparatus for positioning within a tissue tract accessing an underlying body cavity comprising: a seal anchor member having leading and trailing portions; an intermediate portion disposed between the leading and trailing portions; a first positioning member associated with the trailing portion; and a second positioning member associated with the leading portion, the second positioning member having a non-circular shape.
 12. The surgical apparatus of claim 11, wherein the non-circular shape is oblong.
 13. The surgical apparatus of claim 12, wherein the oblong shape of the leading portion facilitates insertion of the leading portion into and through the tissue tract.
 14. The surgical apparatus of claim 11 further comprising at least one port extending generally longitudinally between the trailing and leading portions. 